Add github links for versions

[mec07]

Hey, this seems like an awesome tool!

When I do changelogs I typically add in a link that is clickable so that I can see the diff in github, e.g. [0.1.0]: https://github.com/mec07/rununtil/compare/v0.0.1...v0.1.0 from https://github.com/mec07/rununtil/blob/master/CHANGELOG.md. In this example I've put the links right below each release as I maintain it manually, but a tool like this could just group all the links at the bottom.

Something like that would really help with updating and maintaining my changelogs :)

Let me know if you think it could be a helpful feature or not. I appreciate that you might not want to tie it with github...

[SeanTAllen]

At the moment, the changelog-tool is completely independent of a hosting service and purely interested in the changelog file itself w/ any consideration of external dependencies. I'd like to keep it that way unless we have a specific need to deviate for any of the projects under the Ponylang umbrella or if it was needed by major projects within the Pony ecosystem.

[mec07]

Thanks for considering the feature request.

I do take your point, that link is github specific (bitbucket follows a slightly different convention). The information about where the origin of the repo is located sits inside the .git/config file. One could implement this for the various main providers, so that it's not just github specific.

I guess the counter argument is that then you're tied into git (instead of svn or mercurial etc). I don't think that is the end of the world. The feature would just not be executed if there were no .git file in the repo.

If I (or someone else) were to try to implement this feature as a way to get familiar with the pony language, do you think that the PR would be considered and possibly accepted?